A spokesman for Sturgeon last night said: “The First Minister made it clear that if it is the case of becoming an independent nation within the EU then a second independence referendum is very much on the table.

“She made it clear that once Article 50 is invoked, a two-year clock is ticking and that a referendum would be likely to be held within that timetable.”

“We have not said that a referendum will definitely happen – but if it does then that is fairly likely to be the timetable.”

Party sources say this time senior figures would admit that independence carries economic risks, costs and short-term pain.

Nationalists would argue the UK economy will suffer turmoil anyway and ask voters to choose between the risk of Scotland in Europe or an isolated one in Brexit Britain.

Sturgeon yesterday embarked on a campaign to win over Brussels, meeting European Commission president Jean-Claude Juncker.

REUTERS

Scotland's First Minister Nicola Sturgeon is welcomed by European Commission President Jean-Claude Juncker

She wants to portray Scotland as a ready part of the Celtic block of the EU along with Ireland.

Irish PM Enda Kenny told the EU yesterday about the importance of the Northern Ireland peace process and preserving the Common Travel Area between Northern Ireland and the republic.

The SNP hope that will help them to avoid passport checks between Scotland and England.

Party insiders accept that there are obstacles in the path to a vote.

But they believe obtaining powers from Westminster for a referendum is a formality and that Scotland already fulfils the conditions for EU membership.